Bottom‐up and trait‐mediated effects of resource quality on amphibian parasitism
Abstract Leaf litter subsidies are important resources for aquatic consumers like tadpoles and snails, causing bottom‐up effects on wetland ecosystems. Recent studies have shown that variation in litter nutritional quality can be as important as litter quantity in driving these bottom‐up effects. Resource subsidies likely also have indirect and trait‐mediated effects on predation and parasitism, but these potential effects remain largely unexplored.We generated predictions for differential effects of litter nutrition and secondary polyphenolic compounds on tadpole ( Lithobates sylvatica ) exposure and susceptibility to Ribeiroia ondatrae , based on ecological stoichiometry and community‐ecology theory. We predicted direct and indirect effects on key traits of the tadpole host (rates of growth, development and survival), the trematode parasite (production of the cercaria infective stages) and the parasite's snail intermediate host (growth and reproduction).To test these predictions, we conducted a large‐scale mesocosm experiment using a natural gradient in the concentrations of nutrients (nitrogen) and toxic secondary compounds (polyphenolics) of nine leaf litter species. To differentiate between effects on exposure vs. susceptibility to infection, we included multiple infection experiments including one with constant per capita exposure.We found that increased litter nitrogen increased tadpole survival, and also increased cercaria production by the snail intermediate hosts, causing opposing effects on tadpole per capita exposure to trematode infection. Increased litter polyphenolics slowed tadpole development, leading to increased infection by increasing both their susceptibility to infection and the length of time they were exposed to parasites.Based on these results, recent shifts in forest composition towards more nitrogen‐poor litter species should decrease trematode infection in tadpoles via density‐ and trait‐mediated effects on the snail intermediate hosts. However, these shifts also involve increased abundance of litter species with high polyphenolic levels, which should increase trematode infection via trait‐mediated effects on tadpoles. Future studies will be needed to determine the relative strength of these opposing effects in natural wetland communities. [Correction added after online publication on 5 January 2017: wording changed to ‘which should increase trematode infection via trait‐mediated effects on tadpoles’.]
- 원문이 없습니다.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기